Quantitative and Qualitative Antibody Responses to Immunization With the Pneumococcal Polysaccharide Vaccine in HIV-Infected Patients After Initiation of Antiretroviral Treatment: Results From a Randomized Clinical Trial

Abstract

Background: Pneumococcal vaccination is recommended for human immunodeficiency virus-infected (HIV+) persons; the best timing for immunization with respect to initiation of antiretroviral therapy (ART) is unknown.

Methods: Double-blind, placebo-controlled trial in HIV+ with CD4(+) T cells/µL (CD4) ≥ 200 randomized to receive the 23-valent pneumococcal polysaccharide vaccine (PPV23) or placebo at enrollment, followed by placebo or PPV23, respectively, 9-12 months later (after ≥6 months of ART). Capsular polysaccharide-specific immunoglobin (Ig) G and IgM levels to serotypes 1, 3, 4, 6B, and 23F, and opsonophagocytic killing activity (OPA) to serotypes 6B and 23F were evaluated 1 month postvaccination.

Results: One hundred seven subjects were enrolled, 72 (67.3%) were evaluable (36/group). Both groups had significant increases in pre- to 1-month postvaccination IgG levels, but negligible to IgM, and significant increases in OPA titers to serotype 6B but not to 23F. There were no significant differences between groups in serotype-specific IgM or IgG levels or OPA titers. For the combined groups, there was a significant correlation between serotype-specific IgG and OPA titers to 23F but not to 6B. There was no correlation between CD4, viral load and IgG responses.

Conclusions: In HIV+ with CD4 ≥ 200, delaying PPV23 until ≥6 months of ART does not improve responses and may lead to missed opportunities for immunization.

Keywords: HIV; antibody; antiretroviral treatment; pneumococcal capsular polysaccharides; pneumococcal vaccine.

Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Figures

Figure 1.

Randomization and subjects' follow-up. A total of 107 subjects were enrolled in the study and were randomized to receive 23-valent pneumococcal polysaccharide vaccine (PPV23) at baseline visit (Immediate group) or 1 year later*, and after at least 6 months of antiretroviral treatment (Delayed group). Only subjects that completed the 1 month post-PPV23 visit were included in the analytical group (n = 36 in each group). *1 year visits had a window of 9–12 months.

Figure 2.

Immunoglobin G (IgG) levels to 5 pneumococcal serotypes included in the 23-valent pneumococcal polysaccharide vaccine, 1, 3, 4, 6B and 23F, were measured at baseline, and at 1, 6 and 12 months postvaccination. The number of subjects is indicated at each time point. Gray: Delayed group. Black: Immediate group.